given enough DNA manipulation, you can get yeast to do nearly anything. rob carlson has pointed out the connection from homebrewing to diy biotech for years.
anyone with access to the yeast strain and basic skills in fermentation would be able to grow morphine-producing yeast using a home-brew kit. Because yeast is easy to conceal, grow and transport, criminal syndicates and law-enforcement agencies would have difficulty controlling the distribution of an opiate-producing yeast strain
the craft medicine marketing exists already
Pfizer Releases Vintage Cask-Aged Robitussin. The new up-market blend has a sophisticated flavor profile of cherry, codeine, pseudoephedrine, and hints of citrus.